A German jihadi who returned from Syria has made statements revealing the activities of the Islamic State intelligence service, prior to his trial in January.

According to Sputnik News, German terrorists who worked for the Islamic State intelligence service are providing details about the inner working of the organization's security and intelligence services, including interrogation and torture carried out by Germans in Syria, reported the Suddeutsche Zeitung on Tuesday.

Nils D. served the Islamic State from October 2013 to November 2014, and spent eight months of that time in the employment of what the German newspaper terms a 'Stormtroopers' unit, where he was responsible for the arrest of deserters and so-called dissidents.

According to the Suddeutsche Zeitung, his statements on the nature of his work in Syria correlate with reports from other returnees from Syria, and human rights organizations.

Though Nils D. denies that he himself took part in executions or torture, and only observed them taking place, the newspaper reports that a photograph found on his cell phone shows him holding a gun to the back of a prisoner's head at Manbij jail, where he spent some time working for the terror group.

He has admitted being employed by a 'Stormtrooper' unit in the Syrian city of Manbij, and participating in ten to 15 arrests of people deemed to be enemies of the terror group. To his knowledge, another German is still active in the same Stormtrooper unit.

According to his testimony, shootings and beheadings took place in Manbij in an 'execution marketplace,' where an Islamic State commander was once executed to set an example to others.
The 'Stormtroopers' always appear masked in public, and receive better pay and bonuses for their work.

For example, after the capture of the Iraqi city of Mosul, its fighters were rewarded with loot, said Nils D., who said that fighters were transferred to the unit after a special recommendation.

The jihadi, who comes from the infamous Salafist scene in Dinslaken-Lohberg, North Rhine-Westphalia, is due to go on trial in Dusseldorf in January; he is also scheduled to appear as a witness in two other trials.

He was apprehended by police after he returned from Syria in late 2014 and told a fellow Muslim worshipper about his time with the Islamic State.